Comment on “Isotopic evidence for dominant secondary production of HONO in near-ground wildfire plumes” by Chai et al. (2021)
<p>Chai et al. (2021) recently published measurements of wildfire-derived (WF) oxides of nitrogen (NO<span class="inline-formula"><sub><i>x</i></sub></span>) and nitrous acid (HONO) and their isotopic composition. The method used to sample NO<sp...
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/21/16793/2021/acp-21-16793-2021.pdf |
| Summary: | <p>Chai et al. (2021) recently published measurements of wildfire-derived (WF)
oxides of nitrogen (NO<span class="inline-formula"><sub><i>x</i></sub></span>) and nitrous acid (HONO) and their isotopic
composition. The method used to sample NO<span class="inline-formula"><sub><i>x</i></sub></span>, collection in alkaline solution,
has a known <span class="inline-formula">1:1</span> interference from another reactive nitrogen compound, acetyl
peroxynitrate (PAN). Although PAN is thermally unstable, subsequent
reactions with nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub></span>) in effect extend the lifetime of
PAN many times longer than the initial decomposition reaction would
indicate. This, coupled with the rapid and efficient formation of PAN in WF
plumes, means the NO<span class="inline-formula"><sub><i>x</i></sub></span> measurements reported by Chai et al. were severely
impacted by PAN. In addition, the model reactions in the original paper included neither the reactions of NO<span class="inline-formula"><sub>2</sub></span> with hydroxyl radical (OH) to form
nitric acid nor the efficient reaction of larger organic radicals with
nitric oxide to form organic nitrates (RONO<span class="inline-formula"><sub>2</sub></span>).</p> |
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| ISSN: | 1680-7316 1680-7324 |